Determined products, such as certain food products, must be submitted to a hermetic storage and provided with a clear visual indication to the consumer that the container in which they are presented in the market has not been violated. Since many of these products are of progressive consumption, it is indispensable that after the first opening of the container, the lid which gives access to the inside of the can may be reclosed as many times as necessary during the progressive consumption of the stored product, in order to guarantee the hermeticity of the reclosed can and protect the remaining portion of the content thereof.
There are well known from the prior art the cans with a press-fit lid, in which the latter is press fitted in a peripheral structural ring, which is internal to the upper edge of the body of the can and which is hermetically double seamed to said upper edge. The hermeticity of the content is guaranteed in this type of construction by the fitting of the lid in the seat for the seating and retention thereof, which can be provided in the structural ring that defines the annular upper wall of the can, or in the tubular body of the latter.
In this type of closure, the tamper evident seal, which also guarantees the tightness, is normally defined by an aluminum metallic sheet, which is peripherally double seamed to the upper edge of the body of the can jointly with the structural ring. This inner seal is only visible when the lid is removed and it also requires the use of an instrument for cutting it peripherally, which invariably leaves cutting edges close to the upper opening of the can, causing frequent accidents with wounds in the user's fingers. Besides the inconveniences mentioned above, these known press-fit lids require the use of an instrument, in the form of a lever, for allowing the user to remove the lid from its seat defined in the structural ring. It is not possible for the user to remove this type of lid by using his hands only.
It is also known from the Brazilian patent application PI 0003727-3 a solution in which the plastic lid comprises a sealing portion, which is removably seated and retained in the seat, and a pair of generally semi-annular handles disposed around an upper edge of the sealing portion and having ends incorporated to the latter. The handles can be medianly displaced, from an inoperative position, coplanar to said upper edge, to a raised operative position, after rupturing the breakable means that connect the median regions of the handles to the sealing portion of the plastic lid. In this prior art construction, the plastic lid further incorporates a manually breakable seal strip, provided around the upper end of the tubular body and presenting a lower portion, which is seated and locked under the double seam of the annular upper wall, and an upper portion connected to the handles and to the sealing portion by breakable connecting means.
While it eliminates the deficiencies of the prior lids for cans containing products of progressive consumption, this prior solution of the same applicant still presents some inconveniences. One of said inconveniences relates to the questionable reliability of the retention of the seal strip, as it can be removed if carefully forced upwardly, sliding out from the upper double seam of the can.
Another inconvenience of said prior art lid results from the fact that the opening thereof, by axially pulling it by means of the opposite handles, is abrupt, provoking an undue discharge of the stored product when the lid is removed.
Two more aspects that can be improved are related to the facility with which the handles are accessed for extracting the lid, and to the permanence of the seal strip around the upper edge of the tubular body of the can, usually requiring the application of a cutting instrument for removing it.